Buggy code:
public class DispatcherServlet extends FrameworkServlet { public static final String MULTIPART_RESOLVER_BEAN_NAME = "multipartResolver" ; public static final String LOCALE_RESOLVER_BEAN_NAME = "localeResolver" ; public static final String THEME_RESOLVER_BEAN_NAME = "themeResolver" ; public static final String HANDLER_MAPPING_BEAN_NAME = "handlerMapping" ; public static final String HANDLER_ADAPTER_BEAN_NAME = "handlerAdapter" ; public static final String HANDLER_EXCEPTION_RESOLVER_BEAN_NAME = "handlerExceptionResolver" ; public static final String REQUEST_TO_VIEW_NAME_TRANSLATOR_BEAN_NAME = "viewNameTranslator" ; public static final String VIEW_RESOLVER_BEAN_NAME = "viewResolver" ; public static final String HANDLER_EXECUTION_CHAIN_ATTRIBUTE = ( DispatcherServlet . class . getName ( ) ) + ".HANDLER" ; public static final String WEB_APPLICATION_CONTEXT_ATTRIBUTE = ( DispatcherServlet . class . getName ( ) ) + ".CONTEXT" ; public static final String LOCALE_RESOLVER_ATTRIBUTE = ( DispatcherServlet . class . getName ( ) ) + ".LOCALE_RESOLVER" ; public static final String THEME_RESOLVER_ATTRIBUTE = ( DispatcherServlet . class . getName ( ) ) + ".THEME_RESOLVER" ; public static final String THEME_SOURCE_ATTRIBUTE = ( DispatcherServlet . class . getName ( ) ) + ".THEME_SOURCE" ; public static final String PAGE_NOT_FOUND_LOG_CATEGORY = "org.springframework.web.servlet.PageNotFound" ; private static final String DEFAULT_STRATEGIES_PATH = "DispatcherServlet.properties" ; protected static final Log pageNotFoundLogger = LogFactory . getLog ( DispatcherServlet . PAGE_NOT_FOUND_LOG_CATEGORY ) ; private static final Properties defaultStrategies ; private boolean detectAllHandlerMappings = true ; private boolean detectAllHandlerAdapters = true ; private boolean detectAllHandlerExceptionResolvers = true ; private boolean detectAllViewResolvers = true ; private boolean cleanupAfterInclude = true ; private MultipartResolver multipartResolver ; private LocaleResolver localeResolver ; private ThemeResolver themeResolver ; private List < HandlerMapping > handlerMappings ; private List < HandlerAdapter > handlerAdapters ; private List < HandlerExceptionResolver > handlerExceptionResolvers ; private RequestToViewNameTranslator viewNameTranslator ; private List < ViewResolver > viewResolvers ; public void setDetectAllHandlerMappings ( boolean detectAllHandlerMappings ) { } public void setDetectAllHandlerAdapters ( boolean detectAllHandlerAdapters ) { } public void setDetectAllHandlerExceptionResolvers ( boolean detectAllHandlerExceptionResolvers ) { } public void setDetectAllViewResolvers ( boolean detectAllViewResolvers ) { } public void setCleanupAfterInclude ( boolean cleanupAfterInclude ) { } @ Override protected void onRefresh ( ApplicationContext context ) throws BeansException { } protected void initStrategies ( ApplicationContext context ) { } private void initMultipartResolver ( ApplicationContext context ) { } private void initLocaleResolver ( ApplicationContext context ) { } private void initThemeResolver ( ApplicationContext context ) { } private void initHandlerMappings ( ApplicationContext context ) { } private void initHandlerAdapters ( ApplicationContext context ) { } private void initHandlerExceptionResolvers ( ApplicationContext context ) { } private void initRequestToViewNameTranslator ( ApplicationContext context ) { } private void initViewResolvers ( ApplicationContext context ) { } public final ThemeSource getThemeSource ( ) { } public final MultipartResolver getMultipartResolver ( ) { } protected < T > T getDefaultStrategy ( ApplicationContext context , Class < T > strategyInterface ) { } @ SuppressWarnings ( "unchecked" ) protected < T > List < T > getDefaultStrategies ( ApplicationContext context , Class < T > strategyInterface ) { } protected Object createDefaultStrategy ( ApplicationContext context , Class clazz ) throws BeansException { } @ Override protected void doService ( HttpServletRequest request , HttpServletResponse response ) throws Exception { if ( logger . isDebugEnabled ( ) ) { String requestUri = new UrlPathHelper ( ) . getRequestUri ( request ) ; <START_BUG> logger . debug ( ( ( ( ( "DispatcherServlet<seq2seq4repair_space>with<seq2seq4repair_space>name<seq2seq4repair_space>'" + ( getServletName ( ) ) ) + "'<seq2seq4repair_space>processing<seq2seq4repair_space>request<seq2seq4repair_space>for<seq2seq4repair_space>[" ) + requestUri ) + "]" ) ) ; <END_BUG> } Map < String , Object > attributesSnapshot = null ; if ( WebUtils . isIncludeRequest ( request ) ) { logger . debug ( "Taking<seq2seq4repair_space>snapshot<seq2seq4repair_space>of<seq2seq4repair_space>request<seq2seq4repair_space>attributes<seq2seq4repair_space>before<seq2seq4repair_space>include" ) ; attributesSnapshot = new HashMap < String , Object > ( ) ; Enumeration attrNames = request . getAttributeNames ( ) ; while ( attrNames . hasMoreElements ( ) ) { String attrName = ( ( String ) ( attrNames . nextElement ( ) ) ) ; if ( ( this . cleanupAfterInclude ) || ( attrName . startsWith ( "org.springframework.web.servlet" ) ) ) { attributesSnapshot . put ( attrName , request . getAttribute ( attrName ) ) ; } } } request . setAttribute ( DispatcherServlet . WEB_APPLICATION_CONTEXT_ATTRIBUTE , getWebApplicationContext ( ) ) ; request . setAttribute ( DispatcherServlet . LOCALE_RESOLVER_ATTRIBUTE , this . localeResolver ) ; request . setAttribute ( DispatcherServlet . THEME_RESOLVER_ATTRIBUTE , this . themeResolver ) ; request . setAttribute ( DispatcherServlet . THEME_SOURCE_ATTRIBUTE , getThemeSource ( ) ) ; try { doDispatch ( request , response ) ; } finally { if ( attributesSnapshot != null ) { restoreAttributesAfterInclude ( request , attributesSnapshot ) ; } } } protected void doDispatch ( HttpServletRequest request , HttpServletResponse response ) throws Exception { } @ Override protected long getLastModified ( HttpServletRequest request ) { } @ Override protected LocaleContext buildLocaleContext ( final HttpServletRequest request ) { } protected HttpServletRequest checkMultipart ( HttpServletRequest request ) throws MultipartException { } protected void cleanupMultipart ( HttpServletRequest request ) { } protected HandlerExecutionChain getHandler ( HttpServletRequest request , boolean cache ) throws Exception { } protected void noHandlerFound ( HttpServletRequest request , HttpServletResponse response ) throws Exception { } protected HandlerAdapter getHandlerAdapter ( Object handler ) throws ServletException { } protected ModelAndView processHandlerException ( HttpServletRequest request , HttpServletResponse response , Object handler , Exception ex ) throws Exception { } protected void render ( ModelAndView mv , HttpServletRequest request , HttpServletResponse response ) throws Exception { } protected String getDefaultViewName ( HttpServletRequest request ) throws Exception { } protected View resolveViewName ( String viewName , Map < String , Object > model , Locale locale , HttpServletRequest request ) throws Exception { } private void triggerAfterCompletion ( HandlerExecutionChain mappedHandler , int interceptorIndex , HttpServletRequest request , HttpServletResponse response , Exception ex ) throws Exception { } private void restoreAttributesAfterInclude ( HttpServletRequest request , Map attributesSnapshot ) { } }

Fix:
logger . debug ( ( ( ( ( ( ( "DispatcherServlet<seq2seq4repair_space>with<seq2seq4repair_space>name<seq2seq4repair_space>'" + ( getServletName ( ) ) ) + "'<seq2seq4repair_space>processing<seq2seq4repair_space>" ) + ( request . getMethod ( ) ) ) + "<seq2seq4repair_space>request<seq2seq4repair_space>for<seq2seq4repair_space>[" ) + requestUri ) + "]" ) ) ;